首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   534篇
  免费   13篇
电工技术   25篇
化学工业   74篇
金属工艺   15篇
机械仪表   17篇
建筑科学   5篇
能源动力   9篇
轻工业   24篇
水利工程   2篇
无线电   110篇
一般工业技术   78篇
冶金工业   159篇
原子能技术   5篇
自动化技术   24篇
  2023年   4篇
  2022年   2篇
  2021年   14篇
  2020年   6篇
  2019年   4篇
  2018年   9篇
  2016年   15篇
  2015年   2篇
  2014年   11篇
  2013年   21篇
  2012年   13篇
  2011年   20篇
  2010年   13篇
  2009年   14篇
  2008年   7篇
  2007年   11篇
  2006年   10篇
  2005年   12篇
  2004年   14篇
  2003年   15篇
  2002年   8篇
  2001年   11篇
  2000年   10篇
  1999年   15篇
  1998年   67篇
  1997年   31篇
  1996年   19篇
  1995年   21篇
  1994年   20篇
  1993年   24篇
  1992年   10篇
  1991年   8篇
  1990年   9篇
  1989年   3篇
  1988年   3篇
  1987年   9篇
  1986年   5篇
  1985年   4篇
  1984年   6篇
  1983年   3篇
  1982年   6篇
  1981年   6篇
  1980年   5篇
  1979年   9篇
  1978年   2篇
  1977年   4篇
  1976年   5篇
  1973年   2篇
  1972年   1篇
  1970年   1篇
排序方式: 共有547条查询结果,搜索用时 390 毫秒
61.
62.
A new memory redundancy technique using inverse-gate-electrode flash (ie-flash) memory cells has been developed. The ie-flash can be fabricated by the conventional logic CMOS process, so no additional processes are necessary in using it in system LSIs, and it can be programmed by logic testers. We enhanced the reliability of ie-flash by using some circuits, increasing reliability to endure practical use. This new redundancy technique was successfully implemented in the cache memories of a 32-b RISC microprocessor  相似文献   
63.
Electron paramagnetic (EPR) and ferromagnetic resonance (FMR) have been studied in the system of (Zn,Mn)GeP2 ferromagnetic layer grown on undoped ZnGeP2 single crystal. Strong FMR signals are registered in the wide temperature range up to room temperature. EPR and photo-EPR of intrinsic defects are observed in ZnGeP2 substrate. EPR spectra characteristic of Mn2+ ions on Zn2+ sites in the bulk appear after the growth of the ferromagnetic layer on ZnGeP2 crystal indicating the efficient Mn-diffusion into the bulk crystal by the annealing treatments.  相似文献   
64.
Tunnel-leakage currents become the dominant form of leakage as MOS technology advances. An electric-field-relaxation scheme that suppresses these currents is described. Cosmic-ray-induced multierrors have now become a serious problem at sea level. An alternate error checking and correction architecture for the handling of such errors is also described, along with the application of both schemes in an ultralow-power 16-Mb SRAM. A test chip fabricated by using 0.13-/spl mu/m CMOS technology showed per-cell standby-current values of 16.7 fA at 25/spl deg/C and 101.7 fA at 90/spl deg/C. The chip provided a 99.5% reduction in soft errors under accelerated neutron-exposure testing.  相似文献   
65.
Electron paramagnetic (EPR) and ferromagnetic resonance (FMR) have been studied in the system of (Zn,Mn)GeP2 ferromagnetic layer grown on undoped ZnGeP2 single crystal. Strong FMR signals are registered in the wide temperature range up to room temperature. EPR and photo-EPR of intrinsic defects are observed in ZnGeP2 substrate. EPR spectra characteristic of Mn2+ ions on Zn2+ sites in the bulk appear after the growth of the ferromagnetic layer on ZnGeP2 crystal indicating the efficient Mn-diffusion into the bulk crystal by the annealing treatments.  相似文献   
66.
One of the important factors for designing solar house is to examine the most economic combination what is called optimum design between solar collector area and storage volume for the required energy demand. The result of experimentation gives the fundamental data for completing the computer simulation program that is effectively usable for designing solar house.  相似文献   
67.
68.
This communication describes one pediatric neurosurgeon's personal view of the neurosurgical perspectives in pediatric neurooncology. Various roles of surgery, including histological verification, maximum cytoreduction, neurodecompression and restoration of the cerebrospinal fluid pathway, are emphasized. A pediatric neurosurgeon, who is the first person to make decisions on diagnosis and treatment relating to children with brain tumors, should be up to date with advances in diagnostic and therapeutic methods. Particularly, he or she should be familiar with both the efficacy and the side effects of radiation therapy and chemotherapy to allow selection of the optimum treatment for such children.  相似文献   
69.
An MOCVD-grown InP/InGaAs double-heterojunction bipolar transistor with a step-graded InGaAsP collector is described. This transistor allows high injection current densities over 2.9*10/sup 5/ A/cm/sup 2/, which suggests no significant current blocking related to the wide-gap InP layers. A cutoff frequency of 155 GHz and a maximum oscillation frequency of 90 GHz are obtained at the collector current density of 1.6*10/sup 5/ A/cm/sup 2/.<>  相似文献   
70.
We previously reported three families with type A insulin-resistant syndrome who had mutations, either Asp1179 or Leu1193, in the kinase domain of the insulin receptor. The extreme insulin resistance of these patients was found to be caused by the decreased number of insulin receptors on the cell surface, due to the intracellular rapid degradation (Imamura, T., Takata, Y., Sasaoka, T., Takada, Y., Morioka, H., Haruta, T., Sawa, T., Iwanishi, M., Yang, G. H., Suzuki, Y., Hamada, J., and Kobayashi, M. (1994) J. Biol. Chem. 269, 31019-31027). In the present study, we first examined whether these mutations caused rapid degradation of unprocessed proreceptors, using the exon 13 deleted mutant insulin receptors (DeltaEx13-IR), which were accumulated in the endoplasmic reticulum as unprocessed proreceptors. The addition of Asp1179 or Leu1193 mutation to DeltaEx13-IR caused accelerated degradation of the unprocessed DeltaEx13-IR in the transfected COS-7 cells. Next, we tested whether these mutant receptors were degraded by the proteasome. Treatment with proteasome inhibitors Z-Leu-Leu-Nva-H (MG-115) or Z-Leu-Leu-Leu-H (MG-132) prevented the accelerated degradation of these mutant receptors, resulting in increased amounts of the mutant receptors in the COS-7 cells. Essentially the same results were obtained in the patient's transformed lymphocytes. Finally, we found that these mutant receptors bound to heat shock protein 90 (Hsp90). To determine whether Hsp90 played an important role in the accelerated receptor degradation, we examined the effect of anti-Hsp90 antibody on the mutant receptor degradation. The microinjection of anti-Hsp90 antibody into cells prevented the accelerated degradation of both Asp1179 and Leu1193 mutant insulin receptors. Taken together, these results suggest that Hsp90 is involved in dislocation of the mutant insulin receptors out of the endoplasmic reticulum into the cytosol, where the mutant receptors are degraded by the proteasome.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号